Harrison Hot Springs Screw Pump Flood Control

Our Client’s Opportunity:

In the late 1940’s and early 1950’s, the Village of Harrison Hot Springs experienced significant floods that impacted most of the community. Subsequent to the floods of the 1950’s, the province agreed to contribute to the construction of a dyke to help protect the community. This dyke required the use of a pump to move flowing waters from the Miami River to Harrison Lake in times of high lake levels in order to mitigate the risk of flooding to the Village.

Village of Harrison Hot Springs

The Village of Harrison resides approximately 8.5 meters above sea level and is nestled in the mountainous Fraser Valley. Harrison Lake’s water source is fed by multiple rivers and the annual snow pack runoff. Certain times of the year, these tributaries cause the lake to rise above the level of the Miami River inlet; causing the risk of flooding of the surrounding area. The existing axial pump had worked as designed for over 50 years; however, due to increased environmental requirements surrounding aquatic life and the need to have a better grasp of the water flow from one source to the other, a new system was required. In 2016, the Canadian Department of Fisheries and Oceans legislated that pumps used in this manner must ensure the fish survival rate in excess of 90%.

CTQ was commissioned to provide solutions that would replace the existing pump, increase protection from future flooding, as well as satisfy the current environmental legislation.

With the assistance of CTQ, the Village was able to obtain funding for this project through Provincial and Federal flooding protection programs. The breakdown of the funding sources was, one third from the Federal Government, one third from the Provincial Government and the final third was funded locally. With all three parties coming together, the Village was able to proceed with the project of such significant importance.

Our Approach:

CTQ embraced the challenge the new design requirements would bring. The difficulty was to find a pump that would not only move significant amounts of water quickly to protect the Village from flooding; but also preserve water life at a survival rate exceeding 90% while being passed through the pumps from the Miami River to Harrison Lake.

As a pump of this magnitude could not be located in North America, the search turned international and a solution was found in Holland. Landustrie Worldwide Water Technology of Holland was commissioned to build two Archimedes screw pumps to exact standards and specifications. Each of the screw pumps were 2.8 meters in diameter and 9.0 meters in length and were based on the original design by the Greek philosopher, Archimedes.

Once the size and specifications of the screw pumps were determined, the next step was to design the site plan. Site planning for this project involved placing the key structures to have as little impact as possible to the existing dyke structure. An area of the existing flood control system of box culverts, swing gates and open channel was selected as the location of the new screw pump structure. The existing box culverts were trimmed to serve as the inlet to the new structure.

The open channel and a log bridge spanning the channel were replaced with earth fill over culverts tied to the discharge chamber of the screw pump structure. The discharge culverts were sized to carry the design flow while fitting between the remaining concrete abutments.

Re-grading of the site allowed for improved public use of the scenic setting.

Project Coordination and Construction Management:

Construction of the pump system was coordinated by a local Agassi Contractor who, in turn, used all local Agassi, and Fraser Valley sub-trades to complete the installation of the screw pumps on time and on budget.

Outcome:

The results of this project are incredible. The design of the system based on the principles dating back to 200 BC, with the modern modification of adding electricity to turn the pumps. The two screw pumps are able to turn at rate of 59 RPM and move upwards to 3.0 cubic meters of water per pump per second, while maintaining a survival rate of the water life at an astounding 99% as they pass from one water source to the other. This compared to the original moved the water at a rate of approximately 2.6 cubic meters per second; but, unfortunately had a water life survival rate of 0%.

During design phase, CTQ were cognizant that even colour choice can also have an environmental impact. CTQ contacted fish biologists to determine the best “fish-friendly” option, and this research showed Canary Yellow as the best choice.

Since Landustrie have historically painted their screw pumps black, they questioned the decision to paint the pump blades yellow just to keep the “fish happy”; however, after seeing that there is nearly 100% fish survival rate with the pumps in operation, they have decided to offer Canary Yellow as a standard paint color.

From the initial design discussions to project completion, the entire process took approximately three years. By taking an old design and adding a modern approach, the final product is impressive from all facets including form and function, esthetics and a minimal environmental impact.